Friis Path Loss Calculator

Friis Path Loss is a concept in wireless communication that describes the attenuation of signal power as it propagates from a transmitting antenna to a receiving antenna. It is an essential consideration in designing and analyzing wireless communication systems. This tutorial aims to explain Friis Path Loss, including the associated calculations and formulas. It is relevant to the field of physics, specifically in the study of electromagnetic waves and wireless communication.

Friis Antennas Path Loss Calculator
Friis Path Loss Calculator Results
Path Loss = dB

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Example Formula

Friis Path Loss is calculated using the Friis Transmission Formula, which is expressed as:

Pr = Pt × Gt × Gr × (λ / 4πR)²


  1. Pr: represents the received power at the receiving antenna.
  2. Pt: denotes the transmitted power from the transmitting antenna.
  3. Gt: refers to the gain of the transmitting antenna.
  4. Gr: represents the gain of the receiving antenna.
  5. λ: denotes the wavelength of the signal.
  6. R: represents the distance between the transmitting and receiving antennas.

Who wrote/refined the formula

The Friis Transmission Formula was developed by Danish-American engineer and inventor Harald T. Friis in 1946. Friis made significant contributions to the field of telecommunications, particularly in radio engineering and radar systems. His formula provides a fundamental understanding of the relationship between transmitted power, antenna gains, wavelength, and distance in wireless communication systems. The formula has been widely adopted and applied in the design and analysis of wireless communication networks.

Real Life Application

Friis Path Loss and the associated Friis Transmission Formula find practical applications in various wireless communication systems. Some examples include:

  • Cellular networks: The formula helps engineers optimize the placement and coverage of cellular base stations to ensure efficient signal propagation and minimize path loss.
  • Wireless local area networks (WLANs): It is used in designing and deploying Wi-Fi networks to achieve reliable coverage and data transmission rates.
  • Satellite communication: The formula aids in the design and analysis of satellite links, determining the required transmit power and antenna gains for successful communication over large distances.

Key individuals in the discipline

Harald T. Friis, the creator of the Friis Transmission Formula, was a key individual in the field of telecommunications. His work in radio engineering and radar systems significantly advanced the understanding and practical applications of wireless communication. Friis's contributions laid the foundation for the development of modern wireless technologies and have had a lasting impact on the field of telecommunications.

Interesting Facts

  1. The Friis Transmission Formula assumes ideal conditions and does not account for factors such as multipath interference, signal fading, or environmental obstacles that can affect the actual path loss in real-world scenarios.
  2. The formula highlights the importance of antenna gains and signal wavelength in determining the received power at a given distance.
  3. Advancements in antenna technology and the use of higher frequencies (shorter wavelengths) have led to improved wireless communication systems with reduced path loss and higher data rates.


Friis Path Loss and the Friis Transmission Formula are fundamental concepts in wireless communication. They provide insights into the attenuation of signal power over a distance between transmitting and receiving antennas. Developed by Harald T. Friis, the formula has found widespread use in the design, analysis, and optimization of various wireless communication systems. Understanding path loss is crucial for engineers and researchers working in the field of wireless communications to ensure reliable and efficient signal propagation.

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